Setback in Arab and Western efforts to defuse the revolt peacefully came after world leaders and Syrian activists accused Assad's forces of killing hundreds of people in the bombardment of Homs that began Friday.

UNITED NATIONS - At least 300 people were killed by Syrian forces who began shelling the city of Homs Friday in the bloodiest night in 11 months of upheaval in country. Despite the rising death toll, Russia and China yesterday vetoed a UN Security Council resolution backing an Arab League plan for Syrian President Bashar Assad to step down. The other 13 council members voted in favor of the resolution, which would have said that the council "fully supports" the Arab League plan aimed at ending the bloodshed resulting from Syria's attempt to crush the anti-Assad uprising.

The setback in Arab and Western efforts to defuse the revolt peacefully came after world leaders and Syrian opposition activists accused Assad's forces of killing hundreds of people in the bombardment of Homs that began Friday night.

Dropping the usual diplomatic courtesies, U.S. Ambassador Susan Rice said she was "disgusted" by the Russian and Chinese veto, adding that "any further bloodshed that flows will be on their (Russia's and China's ) hands." Mohammed Loulichki, the UN ambassador of Morocco, the sole Arab member of the 15-nation council, voiced his "great regret and disappointment" and said he was "extremely frustrated" by the failure of the resolution. He added that the Arab League would not abandon its plan.

"It is a sad day for this council, a sad day for all Syrians, and a sad day for democracy," French Ambassador Gerard Araud told the council, adding that Moscow and Beijing were now "complicit in the policy of repression" of Damascus.

Syrian Ambassador Bashar Ja'afari criticized the resolution and denied that Syrian forces killed hundreds of civilians in Homs, saying that "no sensible person" would launch such an attack the night before the Security Council was set to discuss his country.

Russian Ambassador Vitaly Churkin denied that Moscow was standing in the way of a peaceful resolution of of the crisis. "Some influential members of the international community, unfortunately, including those sitting around this table, from the very beginning of the Syrian process have been undermining the opportunity for a political settlement," Churkin said.

Chinese Ambassador Li Baodong said the resolution would not have resolved the issue.

It was the second time that permanent members Russia and China have exercised a double veto on the Syria issue. In October, they killed a European-drafted resolution condemning Syria and threatening it with possible sanctions.

Residents of Homs said Syrian forces began shelling the Khaldiyeh neighborhood of Homs around 8 P.M. on Friday using artillery and mortars.They said at least 36 houses were completely destroyed with families inside.

"We were sitting inside our house when we started hearing the shelling. We felt the bombardment was falling on our heads," said Waleed, a resident of Khaldiyeh.

It was not immediately clear what had prompted Syrian forces to launch such an intense bombardment at a time when diplomats at the UN Security Council were discussing a draft resolution on the Arab League plan calling on Assad to give up power.

One activist said residents were using primitive tools to rescue the people. They feared many people were buried under the rubble.

"There are no ambulances or anything. We are removing the people with our own hands," he said. "We have dug out at least 100 bodies so far; they are placed in the two mosques."

In the cities of Hama and Idlib, activists said hundreds of people took to the streets in solidarity. They chanted in Idlib: "Homs is bombarded, and you are still sleeping?" In Cairo, a crowd stormed the Syrian embassy, smashing furniture and setting fire to parts of the building in protest over the Homs bloodshed. The gate of the embassy was broken and furniture was smashed on the second floor of the building.

In London, 150 people hurled stones at the Syrian embassy, smashing windows and shouting slogans. Police said five men were arrested after breaking into the building and another held for assaulting police. Kuwait's KUNA news agency said Syrians broke into the embassy there at dawn, tore down the flag and injured several security guards. Demonstrators burst into the embassy in Berlin, destroying portraits of Assad and his father.